Small gas turbine engines, often referred to as Auxiliary Power Units, are mounted aboard many types of aircraft to supply pressurized air for environmental control systems and main engine starting as well as shaft horsepower to drive accessories such as electric generators or hydraulic pumps. These engines include in flow series arrangement of a compressor, a combustor, and a turbine. The turbine drives the compressor through a rotating shaft. To keep these engine lightweight and small without sacrificing power it is necessary to operate the compressor at very high speeds, typically in excess of 40,000 rpm. Though a rare occurrence, these compressors sometimes disintegrate spewing out high energy fragments. Should these fragments escape from the engine they can seriously damage the aircraft. Accordingly, engine designers are always striving to develop better containment assemblies for containing the high energy fragments.